A small, new study backs a long-standing claim of advocates of medical marijuana: pain patients can safely use cannabis while taking opioid painkillers, and may actually need fewer pills because of it.

Despite warnings from opponents of medical marijuana, legalizing the drug for medical purposes does not encourage teens to smoke more pot, according to new research that compared rates of marijuana use in Massachusetts and Rhode …

Could a marijuana-based medicine potentially prevent the symptoms of post-traumatic stress disorder (PTSD)? If the findings of a new study in rodents hold up, they may offer a new avenue for treatment of an illness that affects …

A new study in mice has found that activating a receptor affected by marijuana can dramatically reduce cocaine consumption. The research suggests that new anti-addiction drugs might be developed using synthetic versions of …

The idea that “marijuana makes you dumb” has long been embodied in the stereotype of the slow, stupid stoner, seen in numerous Hollywood movies and TV comedies and going unquestioned by much of American culture. But a new …

The U.S. Drug Enforcement Administration (DEA) ruled on Friday that marijuana has “no accepted medical use” and should therefore remain illegal under federal law — regardless of conflicting state legislation allowing medical …

Paranoia is one of the most unpleasant “side effects” of marijuana. It’s also a key experience shared by marijuana smokers and people with schizophrenia. But exactly how does smoking a joint cause the feeling that dark forces are …

As states race to outlaw synthetic drugs sold as “bath salts” or “fake marijuana,” there would seem to be little downside to banning these untested and possibly dangerous chemicals. But prohibiting “legal” intoxicants — many …

Many studies have linked marijuana use with early onset of psychosis. The question is, does smoking marijuana cause earlier psychosis? A new review of 83 studies involving more than 22,000 participants seeks an answer.